Abstract: Objective　The study was conducted to investigate the AIDS related knowledge, attitudes and behaviors in the floating population in Hohhot. Methods　Long distance truck drivers and construction workers were surveyed by fix sampling and stratified cluster sampling respectively. Questionnaire surveys were conducted among them to collect the information related. Results　A total of 681 long distance truck drivers were surveyed, the awareness rate of the transmission routes of HIV/AIDS was 61.1%, and the awareness rate of UNGASS (United Nations General Assembly Special Session) indicators was 13.5%. The proportion of those who discriminated against the people living with HIV/AIDS (PLWHA) in daily life or working settings reached 71.1%. A total of 678 construction workers were surveyed, the awareness rate of the transmission routes of HIV/AIDS was 56.5%, and the awareness rate of UNGASS indicators was 13.0%. The proportion of those discriminating against PLWHA was 74.8%. Over 10% of subjects in both groups were found to have had commercial sex activities during the past year. Conclusion　The AIDS related knowledge awareness rates in the floating population in Hohhot was low. Therefore, health education on AIDS and promotion of condom use is vital to prevent and control AIDS/STD in these population.